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Is the tca9548a 1 to 8 I2C multiplexer?
The TCA9548A multiplexer is interesting in that it has an I2C address (0x70 by default) – and you basically send it a command to tell it which I2C multiplexed output you want to talk to, then you can address the board you want to address.
How does an address byte of the tca9548a look like?
This is how an address byte of the TCA9548A looks like. First 7-bits combine to form the slave address. The last bit of the slave address defines the operation (read or write) to be performed. When it is high (1), a read is selected, while a low (0) selects a write operation.
How is the tca9548a used in Arduino?
The TCA9548A may also be used for Voltage Translation, allowing the use of different bus voltages on each SCn/SDn pair such that 1.8-V, 2.5-V, or 3.3-V parts can communicate with 5-V parts. This is achieved by using external pull-up resistors to pull the bus up to the desired voltage for the master and each slave channel.
Do you short ADDR pins on a tca9548a breakout?
Note that you if you happen to have I2C devices with I2C address 0x70, you will need to short one of the Addr pins on the TCA9548 breakout to Vin in order to make it not conflict. Given that you can have 0x70 thru 0x77, just find one that’s free and you’re good to go! For example, say we want to talk to two HMC5883 breakouts.
The TCA9548A multiplexer is interesting in that it has an I2C address (0x70 by default) – and you basically send it a command to tell it which I2C multiplexed output you want to talk to, then you can address the board you want to address. We suggest using this little helper to help you select the port
How many I2C multiplexers are there in Adafruit breakout?
In theory, you could have 8 of these multiplexers on each of 0x70-0x77 addresses in order to control 64 of the same-I2C-addressed-part. Like all Adafruit breakouts, we put this nice chip on a breakout for you so you can use it on a breadboard with capacitors, and pullups and pulldowns to make usage a snap.
What are the pins for the multiplexer in Adafruit?
A0 A1 A2 – these are the address selection pins for the multiplexer. By default the multiplexer is at address 0x70 and these three pins are pulled low. Connect them to Vin to set the address to 0x71 – 0x77. A0 is the lowest-significant bit (if it is pulled high, it will increase the address by 1).